Oil burner



March 20, 1934.,

E. E. DEHARTA OIL BURNER Filed April 20, 1931 2 Sheets-Sheet l EE- EHHs@ .07@

March 20, 1934. E, E' DEHAR-r 1,951,648

OIL BURNER Filed April 20, 1931 2 Sheets-Sheet 2 E HFIRT ented Mar. 20,1934 UNITED STATES PATENT OFFICE 0lL BURNER Everett E. Dehart, Omaha.Nebr. Application April 20, 1931, Serial No. 531.438 3 (Halimi.l (Cl.158-91) The principal object of my invention is to provide an oil burnerthat will not form undesirable carbon inside its retort on eitherheating flame or pilot flame.

A further object of this invention is to provide an oil burner thatsuccessfully furnishes the correct quantity of air to the amount of fueloil being used and one that delivers such needed air at desirablestrategic locations inside the oil burner retort.

A still further object of this device is to provide an oil burner thatkeeps the fuel oil in a comparatively cool condition until it reachesthe oil burner retort, thereby eliminating possible combustion insidethe fuel delivery pipe.

A still further object of my invention is to provide an oil burner thatwill more successfully break up and commingle the fuel oil with airinside the retort.

A still further object of this invention is to provide an oil burnerthat is economical in manufacture and durable in use.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangement and combinationof the various parts of the device, whereby the objects contemplated areattained as hereinafter more fully set forth,

pointed out in my claims and illustrated in the accompanying drawings,in which:

Fig. 1 is a side sectional view of my invention mounted and ready foruse.

Fig. 2 is a rear view of the hinged gate inside the discharge end of thefan housing.

Fig. 3 is a top plan View of this gate taken on line 3 3 of Fig. 2 andmore fully illustrates its construction.

Fig. 4 is an enlarged side sectional view of the combination air andfuel delivery pipes.

Fig. 5 is an enlarged view of the discharge ends of the combination airand fuel pipes.

Fig. 6 is a top plan sectional view of the oil burner retort showing theentrance therein of the auxiliary air delivery pipe and oil delivery i pxiene of the biggest problem experiencedv in the use of oil burnersusing retorts is the forming of carbon inside the retort, whicheventually renders the oil burner unserviceable. This is espe ciallytrue if the oil burner is of the automatic type which automaticallyreturns to a pilot flame without air carbon rapidly forms inside theretort, eventually putting out the pilot flame and extinguishing the oilburner. I have overcome this by making an-oil burner which furnishessumcient air inside the retort both on heating flame and pilot flame.

I have used the numeral 10 to designate the side wall or door of afurnace. The retort of the invention is generally designated by thenumeral 1l and is secured on the inner side of the member 65 10 andinside the combustion chamber of the furnace or like by suitable meanssuch as bolts. This retort has a detachable lid which I have designatedby the numeral 12. A space exists between the forward upper marginaledge of the retort proper and the forward end portion of the lid 12 andit is through this opening that the flame from the retort is designed toprotrude.

.The numeral 13 designates acomparatively large hollow projectionintegrally formed on the rear 7l end of the retort 11 and designed toextend through the member 10. This hollow projection `13 communicates atone of its ends with the inside rear top of the retort 11, and its otherend communicates with the discharge end portion o f the centrifugal fanhousing 14, as shown in Fig. 1. Rotatably mounted inside the fan housing14 is a centrifugal fan 15 operatively connected to the armature shaft16 of an electric motor 17, shown in dotted lines in Fig. 1. The numeral18 85 designates an intake pipe having one end terminating adjacent themember 10 and its other end communicating with the inlet port of the fanhousing 14. By this arrangement when the fan 15 is rotating. it willobtain its air in a warmed 90 condition from adjacent the surface of themember 10.

From the fan housing 14 the air will normally be injected through themember 13 into the retort where it will strike the downwardly extendingbaille 19. This will cause the air to move to the bottom of the retort11 where it will pick up the fuel gases and then pass out through theforward end of the oil burner in the form of a flame. The gasication ofthe fuel oil inside the retort and its mixture with the air is madepossible by the fact that the retort is inside the furnace and in a hotcondition' for changing the fuel oil into gaseous form. 'Ihe numeral 20designates a horizontal air pipe having its forward end threaded intothe rear end of the retort 11 and terminating lnear the inside bottom ofthat member, as shown in Figures 1 and 6. The numeral 21 des-` ignates apipe connection threaded onto the rear enti of the pipe 20. Besides itstwo open ends this connection has a hollow projection 22 on its top sideand which is in communication with the inside of the connection' towhich it is a part. This hollow projection portion 22 extends upwardlyand rearwardly and has threaded into it the pipe 23. As the fan housing14 is positioned above the member 21, the pipe 23 eventually enters andterminates inside the fan housing 14 adjacent the fan 15, as shown inFig. 1. To more successfully obtain air from the fan 15, the uppermarginal side edge of the pipe 23 extends a considerable distance abovethe floor of the fan housing 14, thereby promoting a quantity of airfrom the fan 15 to enter the pipe 23, pass into the member 21, throughthe pipe 20, and into the retort at a point near the inside bottom ofthe same. The numeral 24 designates a nut threaded into the rear end ofthe connection 21. In the center of this nut is a bore 25 which holdsand supports the forwardly extending fuel oil pipe 26. This pipe 26 hasan outside diameter much smaller than the inside diameter of the member21 and pipe 20, thereby providing a space between the pipe 26 andthemembers in which it is located.

As will be noted from Fig. 4, the pipe 26 has its forward end :dared andextending slightly beyond the forward end of the pipe 20. The numeral 27designates a pipe having one end communicating with the inside of thebore 25 and its other end designed to lead to a source of fuel oil i otshown. The numeral 28 designates'a collar secured in the forward end ofthe pipe- 20 and extending to a point in the same plane with the forwardend of the pipe 26. Integrally formed on the forward marginal edge ofthis collar 28 are a plurality of curved projections 29. By the use ofthese projections 29, the air passing from the end of the pipe 20 willbe given an irregular whirling motion, causing it to more thoroughly mixwith the fuel oil emerging from the forward end of the pipe 26.

The numeral 30 designates a baffle gate hinged at its top and positionedin the discharge end portion of the fan housing 14. In this gate is avertical slot 31. The numeral 32 designates a weight on the rear side ofthe gate 30`and adjacent the slot 31. This weight carries a bolt 33which extends throughthe slot 31 and has the usual manually operated nut34. By this arrangement, the weight 32 is adjustably secured at variouselevations on the gate 30. To prevent undesirable dislocation of theweight 32, I have provided vertical ridges 35 on the gate 30 and at eachside of the weight, as shown in Fig. 3.

By the use of this gate 30, the discharge end of the fan will beyieldingly maintained in a closed condition, thereby forcing a goodlypart of the air cast off by centrifugal force from the fan 15 to enterthe pipe 23. Naturally, the necessary force of the blast of air to openthe gate 30 will depend upon the position of the weight 32. If theweight is close to the hinge portion of the gate, very little energywill be required to move the gate to an open position, while on theother` hand, if the weight 32 is near the bottom of the slot 31, a greatforce will be required to move it to an open position.

When the oil burner is operating on pilot dame, the small ame will be inand projecting from the forward end of the pipe 26. Although when onpilot ame the fan 15 will not be rotating, nevertheless sufficient airmay pass by natural circulation through the member 18 into the fanhousing, thence into the pipe 23 and member 21 and through the pipe 20,which terminates in close proximity to the pipe 26. This air circulationwill be suilicient to furnish desirable quantities of air to the pilotflame and to prevent carbon being formed on the nozzle end of the pipe26 or inside the retort by the pilot flame. As is Well known, whenconditions require the operation of the burner on full llame, this pilotflame is used to ignite the oil burner when the motor 17 is started andthe supply of fuel oil is automatically increased by conventional andwell known control means (not illustrated) so that the device willoperate on heating flame. Due to the flared shape of the forward end ofthe pipe 26 a portion of the pilot flame will be inside this portionwhere it will be protected from being extinguished by the first vairblast from the fan 15. Due to the gate 30, the first rush of this airfrom the fan 15 will pass into the retort 11 by way of the pipe 23 andasthis particular air willbe injected longitudinally with and around thepipe 26, its tendency will be to draw the pilot flame outwardly with theoncoming charge of fuel oil and successfully ignite the burner withoutextinguishing the pilot flame as distinguished from air that would beinjected in theupper portion of 100 the retort and permitted to whipdownwardly onto the asyet delicate pilot flame. As the air from the fan15 increases and the fuel oil flow increases proportionately the flamewill eventually develop into a heating flame projecting from the forwardend of the retort and with such intensity that it cannot be extinguishedby the vblast of air from the centrifugal fan when the pressure in thefan housing is sufficient to open the gate valve 30 and permit thegreater portion of the air blast to pass into. the retort through theconnection 13.

Although after the fan 15 has reached its maximum revolutionsper minute,and the greater volume of air placed in circulation by the fan will passthrough the member 13, a sufficient amount of air will always flowthrough the pipe 20 to prevent any carbon forming in the inside bottomportion of the retort when the oil burner is on heating flame. As wehave seen, the amount of air under pressure forced into the pipe 23.will depend upon the adjustment of the weight 32 on the gate valve 80and the desired amount will depend upon the installation andrequirements of the oil burner. This air that passes through the pipe 20while the burner is on heating flame will prevent the undesirableheating of the pipe 26 and will, as we have seen, by striking themembers 29 assume a whirling motion. This vortex created inside theretort will cause the fuel oil to more successfully mix and gasify withthe air. As is well known, when the oil burner has produced apredetermined temperature, well known automatic and thermostaticmechanism will stop the motor 17 and 135 reduce the flow of fuel oilthrough the pipe 27. This fuel oil is reduced to such an extent in itsflow through the pipe 27 that only a sufficient amount reaches theforward end of the pipe 26 to furnish the pilot flame. As the force ofthe air on the gate valve 30 reduces, the gate will accordingly move toa lowered position foryieldingly enclosing the discharge end of thehousing 14.

The flared portion of the end of the pipe 26 145 will not only protectthe pilot fiame therein and therefrom, but when the motor again starts,the air passing forwardly at each side of the pipe 26 will be guidedforwardly and outwardly by the flared end of that pipe and away fromserious contact with the delicate pilot name until it has reached suchproportions that will not be affected by this current of air. Thisnozzling of the air and fuel oil is adjustably had by the longitudinalmovement of the pipe 20 relative to the pipe 26, and is accomplished byrotating the pipe 20 in the member 21. When the desired location of theend of the pipe 20 is had relative to the forward end of the pipe 26,the pipe should be locked in position by the lock nut 36. The nut 37also locks the pipe 20 to the retort and member 10.

Some ,changes may be made in the construction and arrangement of myimproved oil burner without departing from the real spirit and purposeof my invention, and it is my intention to cover by my claims any modiedforms of structure or use of mechanical equivalents which may bereasonably included within their scope.

I claim:

1. In a device of the class described, a retort, a fan housingcommunicating with the inside top of vsaid retort, a fan in saidhousing, a means for rotating said fan, a pipe having one of its endsterminating inside and in close proximity to the bottom of'said retortand itsl other end in operative communication with the inside of saidfan housing, a second pipe extending inside said rst mentioned pipehaving one end terminating inside said retort and its other end designedto be in communication with a source of fuel oil, a normally closedyieldable valve in the discharge end portion of said fan housingpositioned to direct air from said housing through said rst mentionedpipe when said fan is started into operation and operable to open inproportion to the increase of pressure in said housing to permit arelatively greater amount of air to pass from said housing into saidretort when said i'an is rotating at a comparatively high speed, and ameans for adjusting the yieldability ol' said valve.-

2. In a device of the class described, a retort, a fan housingcommunicating with the inside top of said retort, a centrifugal fan insaid housing, a means for rotating said fan, a pipe having one of itsends terminating inside and in close proximity to the bottom of Vsaidretort and its other end in communication with the inside of said fanhousing; said last mentioned end of said pipe being extended into saidhousing and opening toward said fan to catch and guide air throwntangentially from said fan, a second pipe extending inside said rstmentioned pipe having one end terminating inside said retort and itsother end designed to be in communication with a source of fuel oil, anda normally closed yieldable valve in the discharge end portion of saidfan housing positioned to direct air from said housing through said rstmentioned pipe when said fan is started into operation and operable toopen in proportion to the increase of pressure in said housing to permita relatively greater amount of air to pass from said housing into saidretort when said fan is rotating at a comparatively high speed.

3. In a device of the class described, a retort,

a fan housing communicating with the inside top of said retort, a fan insaid housing, means for rotating said Ian, a yieldable valve in thedischarge end portion of said fan housing normally substantially closingsaid discharge and operable to be opened by the pressure of air withinthe housing upon the operation of said fan, a pipe having one of itsends terminating inside said retort and its other end in operablecommunication with the inside of said fan housing between said fan andsaid valve and a second pipe extending inside said rst mentioned pipehaving one end terminating inside said retort and its other end designedto be in communication with a source of fuel oil.

EVERETT E. DEHART.

